reftable/block: rename block to block_data

The `reftable_block` structure associates a byte slice with a block
source. As such it only holds the data of a reftable block without
actually encoding any of the details for how to access that data.

Rename the structure to instead be called `reftable_block_data`. Besides
clarifying that this really only holds data, it also allows us to rename
the `reftable_block_reader` to `reftable_block` in the next commit, as
this is the structure that actually encapsulates access to the reftable
blocks.

Rename the `struct reftable_block_reader::block` member accordingly.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

reftable/block.c

@@ -210,16 +210,16 @@ int block_writer_finish(struct block_writer *w)
 }
 
 static int read_block(struct reftable_block_source *source,
-		      struct reftable_block *dest, uint64_t off,
+		      struct reftable_block_data *dest, uint64_t off,
 		      uint32_t sz)
 {
 	size_t size = block_source_size(source);
-	block_source_return_block(dest);
+	block_source_release_data(dest);
 	if (off >= size)
 		return 0;
 	if (off + sz > size)
 		sz = size - off;
-	return block_source_read_block(source, dest, off, sz);
+	return block_source_read_data(source, dest, off, sz);
 }
 
 int block_reader_init(struct block_reader *br,
@@ -236,27 +236,27 @@ int block_reader_init(struct block_reader *br,
 	uint8_t block_type;
 	int err;
 
-	err = read_block(source, &br->block, offset, guess_block_size);
+	err = read_block(source, &br->block_data, offset, guess_block_size);
 	if (err < 0)
 		goto done;
 
-	block_type = br->block.data[header_size];
+	block_type = br->block_data.data[header_size];
 	if (!reftable_is_block_type(block_type)) {
 		err = REFTABLE_FORMAT_ERROR;
 		goto done;
 	}
 
-	block_size = reftable_get_be24(br->block.data + header_size + 1);
+	block_size = reftable_get_be24(br->block_data.data + header_size + 1);
 	if (block_size > guess_block_size) {
-		err = read_block(source, &br->block, offset, block_size);
+		err = read_block(source, &br->block_data, offset, block_size);
 		if (err < 0)
 			goto done;
 	}
 
 	if (block_type == BLOCK_TYPE_LOG) {
 		uint32_t block_header_skip = 4 + header_size;
 		uLong dst_len = block_size - block_header_skip;
-		uLong src_len = br->block.len - block_header_skip;
+		uLong src_len = br->block_data.len - block_header_skip;
 
 		/* Log blocks specify the *uncompressed* size in their header. */
 		REFTABLE_ALLOC_GROW_OR_NULL(br->uncompressed_data, block_size,
@@ -267,7 +267,7 @@ int block_reader_init(struct block_reader *br,
 		}
 
 		/* Copy over the block header verbatim. It's not compressed. */
-		memcpy(br->uncompressed_data, br->block.data, block_header_skip);
+		memcpy(br->uncompressed_data, br->block_data.data, block_header_skip);
 
 		if (!br->zstream) {
 			REFTABLE_CALLOC_ARRAY(br->zstream, 1);
@@ -285,7 +285,7 @@ int block_reader_init(struct block_reader *br,
 			goto done;
 		}
 
-		br->zstream->next_in = br->block.data + block_header_skip;
+		br->zstream->next_in = br->block_data.data + block_header_skip;
 		br->zstream->avail_in = src_len;
 		br->zstream->next_out = br->uncompressed_data + block_header_skip;
 		br->zstream->avail_out = dst_len;
@@ -310,21 +310,21 @@ int block_reader_init(struct block_reader *br,
 		}
 
 		/* We're done with the input data. */
-		block_source_return_block(&br->block);
-		br->block.data = br->uncompressed_data;
-		br->block.len = block_size;
+		block_source_release_data(&br->block_data);
+		br->block_data.data = br->uncompressed_data;
+		br->block_data.len = block_size;
 		full_block_size = src_len + block_header_skip - br->zstream->avail_in;
 	} else if (full_block_size == 0) {
 		full_block_size = block_size;
-	} else if (block_size < full_block_size && block_size < br->block.len &&
-		   br->block.data[block_size] != 0) {
+	} else if (block_size < full_block_size && block_size < br->block_data.len &&
+		   br->block_data.data[block_size] != 0) {
 		/* If the block is smaller than the full block size, it is
 		   padded (data followed by '\0') or the next block is
 		   unaligned. */
 		full_block_size = block_size;
 	}
 
-	restart_count = reftable_get_be16(br->block.data + block_size - 2);
+	restart_count = reftable_get_be16(br->block_data.data + block_size - 2);
 	restart_off = block_size - 2 - 3 * restart_count;
 
 	br->block_type = block_type;
@@ -347,20 +347,20 @@ void block_reader_release(struct block_reader *br)
 	inflateEnd(br->zstream);
 	reftable_free(br->zstream);
 	reftable_free(br->uncompressed_data);
-	block_source_return_block(&br->block);
+	block_source_release_data(&br->block_data);
 	memset(br, 0, sizeof(*br));
 }
 
 uint8_t block_reader_type(const struct block_reader *r)
 {
-	return r->block.data[r->header_off];
+	return r->block_data.data[r->header_off];
 }
 
 int block_reader_first_key(const struct block_reader *br, struct reftable_buf *key)
 {
 	int off = br->header_off + 4, n;
 	struct string_view in = {
-		.buf = br->block.data + off,
+		.buf = br->block_data.data + off,
 		.len = br->restart_off - off,
 	};
 	uint8_t extra = 0;
@@ -378,12 +378,12 @@ int block_reader_first_key(const struct block_reader *br, struct reftable_buf *k
 
 static uint32_t block_reader_restart_offset(const struct block_reader *br, size_t idx)
 {
-	return reftable_get_be24(br->block.data + br->restart_off + 3 * idx);
+	return reftable_get_be24(br->block_data.data + br->restart_off + 3 * idx);
 }
 
 void block_iter_seek_start(struct block_iter *it, const struct block_reader *br)
 {
-	it->block = br->block.data;
+	it->block = br->block_data.data;
 	it->block_len = br->restart_off;
 	it->hash_size = br->hash_size;
 	reftable_buf_reset(&it->last_key);
@@ -401,7 +401,7 @@ static int restart_needle_less(size_t idx, void *_args)
 	struct restart_needle_less_args *args = _args;
 	uint32_t off = block_reader_restart_offset(args->reader, idx);
 	struct string_view in = {
-		.buf = args->reader->block.data + off,
+		.buf = args->reader->block_data.data + off,
 		.len = args->reader->restart_off - off,
 	};
 	uint64_t prefix_len, suffix_len;
@@ -528,7 +528,7 @@ int block_iter_seek_key(struct block_iter *it, const struct block_reader *br,
 		it->next_off = block_reader_restart_offset(br, i - 1);
 	else
 		it->next_off = br->header_off + 4;
-	it->block = br->block.data;
+	it->block = br->block_data.data;
 	it->block_len = br->restart_off;
 	it->hash_size = br->hash_size;
 

reftable/block.h

@@ -71,7 +71,7 @@ struct block_reader {
 	uint32_t header_off;
 
 	/* the memory block */
-	struct reftable_block block;
+	struct reftable_block_data block_data;
 	uint32_t hash_size;
 
 	/* Uncompressed data for log entries. */

reftable/blocksource.c

@@ -13,15 +13,15 @@
 #include "reftable-blocksource.h"
 #include "reftable-error.h"
 
-void block_source_return_block(struct reftable_block *block)
+void block_source_release_data(struct reftable_block_data *data)
 {
-	struct reftable_block_source source = block->source;
-	if (block && source.ops)
-		source.ops->return_block(source.arg, block);
-	block->data = NULL;
-	block->len = 0;
-	block->source.ops = NULL;
-	block->source.arg = NULL;
+	struct reftable_block_source source = data->source;
+	if (data && source.ops)
+		source.ops->release_data(source.arg, data);
+	data->data = NULL;
+	data->len = 0;
+	data->source.ops = NULL;
+	data->source.arg = NULL;
 }
 
 void block_source_close(struct reftable_block_source *source)
@@ -34,11 +34,11 @@ void block_source_close(struct reftable_block_source *source)
 	source->ops = NULL;
 }
 
-ssize_t block_source_read_block(struct reftable_block_source *source,
-				struct reftable_block *dest, uint64_t off,
-				uint32_t size)
+ssize_t block_source_read_data(struct reftable_block_source *source,
+			       struct reftable_block_data *dest, uint64_t off,
+			       uint32_t size)
 {
-	ssize_t result = source->ops->read_block(source->arg, dest, off, size);
+	ssize_t result = source->ops->read_data(source->arg, dest, off, size);
 	dest->source = *source;
 	return result;
 }
@@ -48,7 +48,7 @@ uint64_t block_source_size(struct reftable_block_source *source)
 	return source->ops->size(source->arg);
 }
 
-static void reftable_buf_return_block(void *b REFTABLE_UNUSED, struct reftable_block *dest)
+static void reftable_buf_release_data(void *b REFTABLE_UNUSED, struct reftable_block_data *dest)
 {
 	if (dest->len)
 		memset(dest->data, 0xff, dest->len);
@@ -59,8 +59,8 @@ static void reftable_buf_close(void *b REFTABLE_UNUSED)
 {
 }
 
-static ssize_t reftable_buf_read_block(void *v, struct reftable_block *dest,
-				       uint64_t off, uint32_t size)
+static ssize_t reftable_buf_read_data(void *v, struct reftable_block_data *dest,
+				      uint64_t off, uint32_t size)
 {
 	struct reftable_buf *b = v;
 	assert(off + size <= b->len);
@@ -79,8 +79,8 @@ static uint64_t reftable_buf_size(void *b)
 
 static struct reftable_block_source_vtable reftable_buf_vtable = {
 	.size = &reftable_buf_size,
-	.read_block = &reftable_buf_read_block,
-	.return_block = &reftable_buf_return_block,
+	.read_data = &reftable_buf_read_data,
+	.release_data = &reftable_buf_release_data,
 	.close = &reftable_buf_close,
 };
 
@@ -102,7 +102,7 @@ static uint64_t file_size(void *b)
 	return ((struct file_block_source *)b)->size;
 }
 
-static void file_return_block(void *b REFTABLE_UNUSED, struct reftable_block *dest REFTABLE_UNUSED)
+static void file_release_data(void *b REFTABLE_UNUSED, struct reftable_block_data *dest REFTABLE_UNUSED)
 {
 }
 
@@ -113,8 +113,8 @@ static void file_close(void *v)
 	reftable_free(b);
 }
 
-static ssize_t file_read_block(void *v, struct reftable_block *dest, uint64_t off,
-			       uint32_t size)
+static ssize_t file_read_data(void *v, struct reftable_block_data *dest, uint64_t off,
+			      uint32_t size)
 {
 	struct file_block_source *b = v;
 	assert(off + size <= b->size);
@@ -125,8 +125,8 @@ static ssize_t file_read_block(void *v, struct reftable_block *dest, uint64_t of
 
 static struct reftable_block_source_vtable file_vtable = {
 	.size = &file_size,
-	.read_block = &file_read_block,
-	.return_block = &file_return_block,
+	.read_data = &file_read_data,
+	.release_data = &file_release_data,
 	.close = &file_close,
 };
 

reftable/blocksource.h

@@ -12,7 +12,7 @@
 #include "system.h"
 
 struct reftable_block_source;
-struct reftable_block;
+struct reftable_block_data;
 struct reftable_buf;
 
 /*
@@ -24,9 +24,9 @@ void block_source_close(struct reftable_block_source *source);
 /*
  * Read a block of length `size` from the source at the given `off`.
  */
-ssize_t block_source_read_block(struct reftable_block_source *source,
-				struct reftable_block *dest, uint64_t off,
-				uint32_t size);
+ssize_t block_source_read_data(struct reftable_block_source *source,
+			       struct reftable_block_data *dest, uint64_t off,
+			       uint32_t size);
 
 /*
  * Return the total length of the underlying resource.
@@ -37,7 +37,7 @@ uint64_t block_source_size(struct reftable_block_source *source);
  * Return a block to its original source, releasing any resources associated
  * with it.
  */
-void block_source_return_block(struct reftable_block *block);
+void block_source_release_data(struct reftable_block_data *data);
 
 /* Create an in-memory block source for reading reftables. */
 void block_source_from_buf(struct reftable_block_source *bs,

reftable/iter.c

@@ -114,7 +114,7 @@ static void indexed_table_ref_iter_close(void *p)
 {
 	struct indexed_table_ref_iter *it = p;
 	block_iter_close(&it->cur);
-	block_source_return_block(&it->block_reader.block);
+	block_source_release_data(&it->block_reader.block_data);
 	reftable_free(it->offsets);
 	reftable_buf_release(&it->oid);
 }
@@ -128,7 +128,7 @@ static int indexed_table_ref_iter_next_block(struct indexed_table_ref_iter *it)
 		return 1;
 	}
 
-	block_source_return_block(&it->block_reader.block);
+	block_source_release_data(&it->block_reader.block_data);
 
 	off = it->offsets[it->offset_idx++];
 	err = table_init_block_reader(it->table, &it->block_reader, off,

reftable/reftable-blocksource.h

@@ -21,28 +21,28 @@ struct reftable_block_source {
 
 /* a contiguous segment of bytes. It keeps track of its generating block_source
  * so it can return itself into the pool. */
-struct reftable_block {
+struct reftable_block_data {
 	uint8_t *data;
 	size_t len;
 	struct reftable_block_source source;
 };
 
 /* block_source_vtable are the operations that make up block_source */
 struct reftable_block_source_vtable {
-	/* returns the size of a block source */
+	/* Returns the size of a block source. */
 	uint64_t (*size)(void *source);
 
 	/*
 	 * Reads a segment from the block source. It is an error to read beyond
 	 * the end of the block.
 	 */
-	ssize_t (*read_block)(void *source, struct reftable_block *dest,
-			     uint64_t off, uint32_t size);
+	ssize_t (*read_data)(void *source, struct reftable_block_data *dest,
+			uint64_t off, uint32_t size);
 
-	/* mark the block as read; may return the data back to malloc */
-	void (*return_block)(void *source, struct reftable_block *blockp);
+	/* Mark the block as read; may release the data. */
+	void (*release_data)(void *source, struct reftable_block_data *data);
 
-	/* release all resources associated with the block source */
+	/* Release all resources associated with the block source. */
 	void (*close)(void *source);
 };